I have the same issue and I am also getting selected device has no output controls and cannot hear anything through my headphones unless I have the volume turned all the way up. I have OS10.13.6 on my mac and I have the mic and headphones pulled into the Scarlett 2i2 that I have. The mic is recording fine even though I cannot hear it through my headphones.
So which is it, are you having the same issue (“External mike with Scarlett 2i2 doesn’t record”), or “The mic is recording fine”
Which version of Audacity? (look in “Audacity menu > About Audacity”.)